Archive for the ‘Tsunami, Earthquakes’ Category

Infrared emissions above the epicenter increased dramatically in the days before the devastating earthquake in Japan, say scientists.

Geologists have long puzzled over anecdotal reports of strange atmospheric phenomena in the days before big earthquakes. But good data to back up these stories has been hard to come by.

In recent years, however, various teams have set up atmospheric monitoring stations in earthquake zones and a number of satellites are capable of sending back data about the state of the upper atmosphere and the ionosphere during an earthquake.

Last year, we looked at some fascinating data from the DEMETER spacecraft showing a significant increase in ultra-low frequency radio signals before the magnitude 7 Haiti earthquake in January 2010

Today, Dimitar Ouzounov at the NASA Goddard Space Flight Centre in Maryland and a few buddies present the data from the Great Tohoku earthquake which devastated Japan on 11 March. Their results, although preliminary, are eye-opening.

They say that before the M9 earthquake, the total electron content of the ionosphere increased dramatically over the epicentre, reaching a maximum three days before the quake struck.

At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake. In other words, the atmosphere was heating up.

These kinds of observations are consistent with an idea called the Lithosphere-Atmosphere-Ionosphere Coupling mechanism. The thinking is that in the days before an earthquake, the great stresses in a fault as it is about to give cause the releases large amounts of radon.

The radioactivity from this gas ionises the air on a large scale and this has a number of knock on effects. Since water molecules are attracted to ions in the air, ionisation triggers the large scale condensation of water.

But the process of condensation also releases heat and it is this that causes infrared emissions. “Our first results show that on March 8th a rapid increase of emitted infrared radiation was observed from the satellite data,” say Ouzounov and co.

These emissions go on to effect the ionosphere and its total electron content.

It certainly makes sense that the lithosphere, atmosphere and ionosphere are coupled in a way that can be measured when one of them is perturbed. The question is to what extent the new evidence backs up this idea.

The Japan earthquake is the largest to have struck the island in modern times and will certainly turn out to be among the best studied. If good evidence of this relationship doesn’t emerge from this data, other opportunities will be few and far between.

It’s the stuff legends are made of. On this day 199 years ago, the first in a series of catastrophic earthquakes rocked the Midwest along the New Madrid seismic zone. Although the epicenter of the December 16th quake was in northeast Arkansas, the magnitude of the quake reportedly caused church bells to ring along the East coast.

As the graphic above shows, an major earthquake in the New Madrid zone (of magnitude 6.0 or more) would severely affect Arkansas, Tennessee, Missouri, Kentucky, Illinois, Indiana, and Ohio. Several other states would be affected, ranging from Minnesota to Florida.

It’s hard to imagine a natural disaster on that scale today. For this reason, FEMA is leading a national-level exercise in May of 2011 (NLE 2011) simulating a major earthquake along the New Madrid fault. We’re bringing all the relevant team members to the table to make the exercise as realistic as possible – federal/state/local governments, the private sector, non-profit and faith-based groups, the public, and even the international community. FEMA leaders will provide more details on NLE 2011 as it approaches, so watch the blog for more details.

If the 199th anniversary of New Madrid serves a purpose today, it’s that individuals and communities need to plan for what we call a “maximum of maximums” event — a large-scale, catastrophic event. It may be gloomy to think about, but it’s necessary to plan for the unexpected, so whether you live along the New Madrid fault line or in the Pacific Northwest, take a few minutes today to be informed about the possible disasters in your community.

We sincerely hope America never has to respond to a major earthquake in the New Madrid zone, but we need to be prepared. Visit Ready.gov for earthquake preparedness tips and other ways you can get prepared.

We want to use this blog to share ideas and continue the conversation, so leave a comment about how your family / organization / company is preparing for a “maximum of maximums” event.

Like this:

An aerial handout photo from the Icelandic Coast Guard shows melting ice caused by a volcanic eruption at Eyjafjalla Glacier in southern Iceland April 14, 2010. The volcanic eruption on Wednesday partially melted a glacier, setting off a major flood. Photo: Arni Saeberg/Handout

A thaw of Iceland’s ice caps in coming decades caused by climate change may trigger more volcanic eruptions by removing a vast weight and freeing magma from deep below ground, scientists said on Friday.

They said there was no sign that the current eruption from below the Eyjafjallajokull glacier that has paralysed flights over northern Europe was linked to global warming. The glacier is too small and light to affect local geology.

“Our work suggests that eventually there will be either somewhat larger eruptions or more frequent eruptions in Iceland in coming decades,” said Freysteinn Sigmundsson, a vulcanologist at the University of Iceland.

“Global warming melts ice and this can influence magmatic systems,” he told Reuters. The end of the Ice Age 10,000 years ago coincided with a surge in volcanic activity in Iceland, apparently because huge ice caps thinned and the land rose.

“We believe the reduction of ice has not been important in triggering this latest eruption,” he said of Eyjafjallajokull. “The eruption is happening under a relatively small ice cap.”

Carolina Pagli, a geophysicist at the University of Leeds in England, said there were risks that climate change could also trigger volcanic eruptions or earthquakes in places such as Mount Erebus in Antarctica, the Aleutian islands of Alaska or Patagonia in South America.

MAGMA

“The effects would be biggest with ice-capped volcanoes,” she said. “If you remove a load that is big enough you will also have an effect at depths on magma production.”

She and Sigmundsson wrote a 2008 paper in the scientific journal Geophysical Research Letters about possible links between global warming and Icelandic volcanoes.

That report said that about 10 percent of Iceland’s biggest ice cap, Vatnajokull, has melted since 1890 and the land nearby was rising about 25 millimetres (0.98 inch) a year, bringing shifts in geological stresses.

They estimated that the thaw had led to the formation of 1.4 cubic km (0.3 cubic mile) of magma deep below ground over the past century.

At high pressures such as under an ice cap, they reckon that rocks cannot expand to turn into liquid magma even if they are hot enough. “As the ice melts the rock can melt because the pressure decreases,” she said.

Sigmundsson said that monitoring of the Vatnajokull volcano since 2008 suggested that the 2008 estimate for magma generation was “probably a minimum estimate. It can be somewhat larger.”

He said that melting ice seemed the main way in which climate change, blamed mainly on use of fossil fuels, could have knock-on effects on geology. The U.N. climate panel says that global warming will cause more floods, droughts and rising seas.

Experts say suggestions that climate change could trigger more volcanoes and earthquakes are speculative, but there is enough evidence to take the threat seriously

Smoke and steam hang over the volcano under the Eyjafjallajokull glacier in Iceland. Volcanic ash drifting across the Atlantic forced the cancellation of flights in Britain and disrupted air traffic across Europe last week.
Photograph: Jon Gustafsson/AP

Scientists today called for wide-ranging research into whether more volcanoes, earthquakes, landslides and tsunamis could be triggered by rising global temperatures under global warming.

Significant warming of the atmosphere in the distant past can be linked to changes in geological activity, they say. Suggestions that climate change predicted for coming decades could bring similar changes remain speculative, but the scientists say there is enough evidence to take the threat seriously. Some experts have already linked current levels of global warming to rockfalls and landslides in mountain regions.

Richard Betts, a climate modeller at the Met Office Hadley Centre in Exeter, said: “This is a new area of academic research with potentially interesting implications. It was previously assumed there was no link at all between climate change and these events, but it is possible to speculate that climate change might make some more likely. If we do get large amounts of climate change in the long term then we might see some impacts.”

He said there was no evidence that current levels of global warming were influencing events such as last week’s earthquake in China that killed hundreds of people and the volcanic eruption in Iceland that grounded flights across Europe.

Experts say global warming could affect geological hazards such as earthquakes because of the way it can move large amounts of mass around on the Earth’s surface. Melting glaciers and rising sea levels shift the distribution of huge amounts of water, which release and increase pressures through the ground.

These pressure changes could make ruptures and seismic shifts more likely. Research from Germany suggests that the Earth’s crust can sometimes be so close to failure that tiny changes in surface pressure brought on my heavy rain can trigger quakes. Tropical storms, snowfall and shifting tides have all been linked to shifts in seismic activity.

Writing in a special series of scientific papers on the topic published today by the Royal Society, Bill McGuire, head of the Benfield Hazard Research Centre at University College London, says: “In relation to anthropogenic climate change, modelling studies and projection of current trends point towards increased risk in relation to a spectrum of geological and geomorphological hazards in a warmer world, while observations suggest that the ongoing rise in global average temperatures may already be eliciting a hazardous response from the geosphere.”

He adds: “In order to improve knowledge and reduce uncertainty, a programme of focused research is advocated … The IPCC [Intergovernmental Panel on Climate Change] is also strongly exhorted to address more explicitly in future assessments the impact of anthropogenic climate change on the geosphere, together with its manifold potentially hazardous consequences.”

McGuire says: “No increase in the global incidence of either volcanic activity or seismicity has been identified to date … It may be the case that modulation of potentially hazardous geological processes due to anthropogenic climate change proves too small a signal to extract from the background noise of normal geophysical activity, at least in the short to medium term.”

Like this:

One of the strongest series of earthquakes ever to hit the United States happened not in Alaska or along California’s San Andreas fault, but in southeast Missouri along the Mississippi River.

In 1811 and 1812, the New Madrid fault zone that zig zags through five states shook so violently that it shifted furniture in Washington, D.C., and rang church bells in Boston. The series of temblors changed the course of the Mississippi River near Memphis, and historical accounts claim the river even flowed backward briefly.

Geologists consider the New Madrid fault line a major seismic zone and predict that an earthquake roughly the magnitude of the Haiti earthquake (7.0 on the Richter scale) could occur in the area during the next 50 years.

That forecast is of particular concern because the New Madrid zone sits beneath one of the country’s most economically distressed areas – the Delta. In many counties in the Mississippi Delta, the poverty level is triple the national average.

Moreover, the area is comparatively less prepared to deal with a huge earthquake than are other seismically active areas in the US, says Mark Ghilarducci, vice president of James Lee Witt Associates, a crisis and emergency management consulting company in Washington.

“There have not been enough resources applied for retrofitting that there could be,” Mr. Ghilarducci says. “I would like to see far more retrofit programs, strengthening of buildings, especially masonry buildings, tying down bridges. That builds resiliency in a community.”

Efforts to Prepare

Neither the federal government nor local governments are unaware of the threat.

Numerous interstate task forces and coalitions have organized over the last decade to prepare for a catastrophic earthquake. Education programs focused on survival kits and family disaster planning occur yearly in states. Yet, experts say, few families have kits in their homes.

Last November, the Obama administration’s Long Term Disaster Recovery Working Group held five stakeholder meetings around the country, including Memphis. They solicited input on how “to improve long-term disaster recovery with a particular focus on catastrophic disasters.”

Faults in Region Are Active

The meetings were co-chaired by Homeland Security Secretary Janet Napolitano and Housing and Urban Development Secretary Shaun Donovan.

The New Madrid fault zone crosses five state lines and the Mississippi River in at least three places. It extends from northeast Arkansas through southeast Missouri and into western Tennessee, western Kentucky, and southern Illinois.

In the 1800s, few people lived in the region. Today, it is densely populated and includes Memphis and St. Louis.

“All the faults are active,” says Haydar Al-Shukri, director of Arkansas Earthquake Center. “We would see an earthquake 10 times larger than the Haitian earthquake or even those in California because of the amount of distance the seismic waves of the earthquake would travel.”

Delta Rife With Poverty

Even with government efforts at preparation, much remains to be done, says Ghilarducci, the emergency management consultant.

In many areas, people still live in shanties. Health care is sparse. Even clean water is scarce in some places. Often, public and private buildings, are decades-old and fragile. They have yet to be retrofitted or strengthened. Hundreds of towns could see severe structural damage, and large segments of the population displaced, Dr. Al-Shukri says.

“You still have a lot of places with cinderblock structures,” he adds. “That is the worst kind of structure you can build in a place with earthquakes. These concrete blocks are very stiff, and they do not have flexibility, so they can’t yield to seismic vibrations.”

The challenges are particularly daunting in rural areas. Given that federal dollars most often target metropolitan areas, people could be cut off from supplies for days. To help mitigate this threat, Memphis Light, Gas & Water was given a grant of $2.6 million to reduce the risk to its electrical grid from earthquakes.

“Disasters aren’t entirely a government issue,” Ghilarducci says. “If people live further out, they need to have something to be self-sufficient for a couple of days until help can reach them.”

Like this:

In October 2008, Patrick Charles – a former professor at the Geological Institute of Havana – told a reporter from Haiti’s Le Matin newspaper that, “conditions are ripe for major seismic activity in Port-au-Prince.”

Charles’ statements reiterated the positions of five prominent scientists who presented a paper – at the March 2008 Caribbean Geological Conference – stating that a fault zone on the south side of the island of Hispaniola (which Haiti shares with the Dominican Republic) “posed a major seismic hazard.”

Both Charles and the five members of the conference group pointed to the large fault – part of the Enriquillo Fault Zone – that traverses the city of Port-au-Prince.

“We were concerned about it,” conference paper co-author Paul Mann, a senior research scientist at the University of Texas’ Institute for Geophysics, told CNN. “The problem with these kinds of strikes is that they can remain quiescent — dormant — for hundreds of years. So it’s hard to predict when they’ll occur.”

In the Le Matin article, Professor Charles cited numerous then-recent tremors that occurred in the Haitian townships of Delmas, Croix des Bouquets, La Plaine and Petionville. The Enriquillo fault starts in Petionville and follows the southern peninsula, ending in the town of Tiburon – which was twice destroyed by earthquakes in the 18th century.

“Minor tremors such as these,” Charles told Le Matin in October 2008, “usually signal a larger earthquake to come.”

According to the U.S. Geological Survey there have been 12 major earthquakes measuring 7.0 or greater on the Richter Scale in the Carribean in the past 500 years. In 1946, a magnitude 8.0 near Hispaniola caused a tsunami and left 20,000 people homeless.

Professor Charles told Le Matin that it had been 200 years since any major seismic activity had occurred in Port-au-Prince, and the building stress and energy beneath the earth’s surface could one day result in an earthquake measuring 7.2 striking the capital city.

Last Tuesday’s quake measured 7.0 on the Richter Scale.

Noting that Haitian government officials often discuss plans to deal with a potential calamitous earthquake but never move to put measures in place addressing such an event, Charles described the devastating scenarios the world has watched unfold this past week.

“This would be an event of catastrophic proportions in a city with loose building codes and an abundance of shanty-towns built in ravines,” Charles told the Haitian newspaper.

Charles’ 2008 warning included the potential for a tsunami flooding La Plaine and the complete destruction of Morne l’Hopital – an area teeming with flimsy shanty-towns.

“If we thought the recent back-to-back hurricanes were devastating,” Le Matin wrote at the time, “they surely will pale in comparison to a major earthquake in the densely populated Haitian capital.”

Like this:

CHICAGO — Haiti and its neighbors must prepare themselves for more massive quakes after the devastating tremors this week increased pressure along a lengthy fault line, scientists warned Friday.

Paul Mann, a senior research scientist at the Institute for Geophysics at the University of Texas at Austin, warned that just because the rebuilding process had started people shouldn’t assume the risk was over.

“This relief of stress along this area near Port-au-Prince may have actually increased stress in the adjacent segments on the fault,” he told AFP.

Researchers have already begun to work on models to try to predict how the stress changes resulting from the 7.0-magnitude quake which struck Tuesday is affecting the adjacent segments of the fault.

“This fault system is hundreds of kilometers long and the segment that ruptured to form this ear quake is only 80 kilometers long,” Mann said in a telephone interview.

“There are many more segments which are building up strain where there haven’t been earthquakes for hundreds of years.

“Potentially any one of these segments could cause an earthquake similar to that which happened in Haiti.”

There are, thankfully, only two major population centers along the fault: Port-au-Prince and Kingston, Jamaica.

But as demonstrated in the chaos which followed Tuesday’s tremor, the impact of a quake of that magnitude can be “paralyzing,” Mann said.

Adding to the danger is the fact that the segment which broke was not among those closest to Port-au-Prince.

And there is a second fault system in the north of Haiti which extends to the Dominican Republic which has not ruptured in 800 years and has built up sufficient pressure for a 7.5 magnitude quake.

“The question is when are those going to rupture,” Mann said, adding that it is very difficult to predict “whether or not that’s going to happen next week or 100 years.”

Eric Calais, a French geophysicist who works at Purdue University in Indiana, is among those trying to assess the danger.

He had warned Haitian officials years ago of dangerous pressure in the fault which caused this week’s devastating quake, but little could be done to reinforce the desperately poor nation’s weak buildings.

“The Haitian government is not to blame in this,” Calais told AFP.

“They listened to us carefully and they knew what the hazard was. They were very concerned about it and they were taking steps. But it just happened too early.”

Calais began researching the fault line in 2003 and soon took his initial findings to the Haitian government, even meeting with the prime minister.

In March 2008 he and Mann presented a paper showing that the fault had built up sufficient pressure to cause a 7.2 magnitude quake.

But they could not pinpoint when the quake might strike and the government was occupied with recovering from a series of four hurricanes which struck that year.

While the government had begun work on an emergency response plan, little could be done to retrofit and strengthen key buildings such as hospitals, schools and government buildings from which rescue operations could be organized.

“It’s a poor country,” Calais said. “Strengthening a building to resist a large earthquake can be as costly as replacing the building.”

The devastation will allow Haiti to rebuild stronger than before, Calais said, noting that there are relatively cheap engineering solutions that can be applied to ensure that new buildings will not collapse in the next quake.

“It’s very important for Port-au-Prince to rebuild properly,” he added. “There are other segments of that fault that could rupture in the future.”